Today, a building site does not need to obtain all electrical power from the public utility grid, or simply, “grid”. There are alternative energy sources (AES) to the grid, for example photovoltaic (PV) solar, wind, geothermal, etc., that may be available. In most cases, an AES is in close proximity to the building site. For example, in the case of the PV solar, the solar panel may be located adjacent to or on the roof of a building. In addition, the building site may have access to locally stored power, e.g., in the form of lithium ion batteries or fuel cells.
Prior art equipment configurations used to produce, convert, distribute, and store power for or to a building site are complex and expensive, with many pieces of equipment and many interfaces. What is needed is a simple, relatively inexpensive system to produce, convert, distribute and store electrical power for a building site. Such a system should direct power from one or more sources to meet the demand of one or more loads. The power provided to an internal DC bus in the system is equal to the power drawn from the DB bus and sent to the one or more loads. When the voltage on the DC bus is fixed, the current transmitted to the bus necessarily is the same as the current transmitted from the bus. Therefore, what is needed is a controller that adjusts or limits input current from the sources so the current transmitted to the bus is the same as the current transmitted from the bus.